1. Field of the Invention
The present invention belongs to a technical field of connector for module (hereinafter it may be simply referred to as connector) that is used for a module wherein semiconductor chips are mounted on a rectangular board and conductive pads are provided on a front side of the board (hereinafter simply referred to as module). In particular, the present invention relates to countermeasures against heat, electromagnetic waves, etc. to which a connector for module is exposed.
2. Related Art
Modules of this kind include those in which semiconductor chips such as semiconductor memories are mounted. A module connector is used extensively, which connects a module of this kind to a printed circuit board such as a mother board in a position wherein the board surface of the module is approximately parallel to the printed circuit board. This connector has an approximately U-shaped form to correspond to the front side, left side and right side of the module, respectively. A receiving part of the connector corresponding to this front side is provided with a groove that will receive the front side of the module. The groove is provided with contacts that will contact conductive pads while allowing the conductive pads to move in a direction of insertion/withdrawal when the module is in an insertion/withdrawal position in which the rear side thereof is lifted more in comparison with its level in the connection position. Two arms of the connector corresponding to the left side and the right side of the module are arranged so that their top ends can undergo elastic deformation leftward and rightward, respectively, and each arm is provided with a engaging claw on the inner side of the top end thereof. The connector is mounted on the printed circuit board by soldering the solder tails of the contacts onto the printed circuit board. When the module is to be fitted into the connector, first, the module is set in the insertion/withdrawal position and the front side of the module is inserted between the contacts. Next, the rear side of the module is pushed downward. As a result, the conductive pads and contacts are made to contact with each other. When the left side and the right side are pressed against the arms, the top ends of the arms will undergo elastic deformation outward and the engaging claws will fit into the left side and the right side of the module. As a result, the module will be retained in the connection position. When the fitted module is to be disconnected from the connector, the top ends of the arms are made by fingers to undergo elastic deformation outward to release the engaging claws from the module. The rear side of the module will be lifted by the elastic recovering forces of the contacts and the module will be shifted from the connection position into the insertion/withdrawal position. Thus the module can be withdrawn from the space between the contacts.
Semiconductor memories show a tendency to increase their heat generation significantly. It is due to, for example, quickening of their operating speed that is a result of the speed-up of the CPU. This thermal load may cause deformation of the arms of the connector, which in turn may result in loss of the engaging function of the engaging members. Outward elastic deformation of the top ends of the arms by fingers may cause plastic deformation of the arms. The loss of the engaging function and the deformation may cause defective connection and/or disconnection of the module. Heat generation also poses a problem that it may make the operation of the semiconductor memories unstable. Moreover, if the connector is exposed to the effects of ambient electromagnetic waves or the like, the operation of the circuits may become unstable. The above-mentioned problems are not limited to the connectors for modules having semiconductor memories. They are common to connectors for modules having general semiconductor chips.